Dryer appliances generally include a cabinet with a drum mounted therein. In many dryer appliances, a motor rotates the drum during operation of the dryer appliance, e.g., to tumble articles located within a chamber defined by the drum. Typical dryer appliances also generally include a heating assembly that passes heated air through the chamber of the drum in order to dry moisture-laden articles disposed within the chamber. This internal air then passes from the chamber through a vent duct to an exhaust conduit, through which the air is exhausted from the dryer appliance. Typically, an air handler (such as a blower) is utilized to flow the internal air from the vent duct to the exhaust duct. When operating, a blower may pull air through itself from the vent duct, and this air may then flow from the blower to the exhaust conduit.
Consumer demand and regulation have increased the need for energy efficient appliances. Moreover, decreased energy consumption is generally advantageous. This is especially true for dryer appliances, which may be one of the primary energy consumption sources within a home. Specifically, the heating assembly may consume a relatively large amount of energy. Some appliances provide for a heating assembly that can vary heat or energy output setting according to certain properties (e.g., size) of the overall load of articles placed within the drum. A suitable heat or energy setting may ensure that the heating assembly does not operate for too long or at too high of a setting, thus minimizing energy consumption. However, when operating the dryer appliance, it may be difficult to determine the correct heat or energy output setting for the heating assembly. Many users are unable to correctly evaluate properties such as load size. Although some existing systems provide features for determining load size, for example, by solely monitoring temperature changes within the drum, such systems may be inaccurate under certain conditions. Further systems may be undesirably complex and/or difficult to implement, thus increasing their reliability and the overall cost of the dryer appliance.
As a result, it would be advantageous to provide a dryer appliance that could automatically (e.g., without a user estimation or input) determine a load size of articles within a drum. It would be further advantageous to provide a dryer appliance that could make such determinations accurately, reliably, and inexpensively. Moreover, energy consumption may be advantageously reduced if such a system could automatically control a heat or energy output based on such load size determinations.